Abstract

A method of calculating the first‐order concentration dependence of the self‐diffusion coefficient of spherical Brownian particles interacting with one another is derived on the basis of the time‐independent (i.e., stationary) form of the two‐particle Smoluchowski equation. The method is applied to the cases of hard spheres with and without hydrodynamic interactions. The hydrodynamic interactions are taken into account by use of Oseen’s and Felderhof ’s approximations for the diffusiontensors. Explicit expressions for the self‐diffusion coefficient are obtained which are in agreement with previous ones based on the time‐dependent (i.e., nonstationary) form of the Smoluchowski equation.